password_verify

Descrição

booleanpassword_verify
( string$password
, string$hash
)

Verifies that the given hash matches the given password.

Note that password_hash() returns the algorithm, cost and salt
as part of the returned hash. Therefore, all information that's needed to verify
the hash is included in it. This allows the verify function to verify the hash
without needing separate storage for the salt or algorithm information.

Veja Também

User Contributed Notes 4 notes

If you get incorrect false responses from password_verify when manually including the hash variable (eg. for testing) and you know it should be correct, make sure you are enclosing the hash variable in single quotes (') and not double quotes (").

PHP parses anything that starts with a $ inside double quotes as a variable:

<?php
// this will result in 'Invalid Password' as the hash is parsed into 3 variables of
// $2y, $07 and $BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq
// due to it being enclosed inside double quotes
$hash = "$2y$07$BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq";

// this will result in 'Password is valid' as variables are not parsed inside single quotes
$hash = '$2y$07$BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq';

The function password_verify() uses constant time. This makes it safe against timing attacks. Don't use crypt($password_database) === crypt($password_given_by_login), since there is no protection against timing attacks!

If you don't want to use password_verify(), then have a look at hash_equals(), which also runs a timing attack safe string comparison.